Initial commit of WIP

* `erlang.mk` @6b42bd7 instead of `rebar`
* Simple `cowboy` REST app.
* Simple distributed cache system (changed from ETS to mnesia).
* Reverted to ETS for simple testing.
* All files compiled and run.
* Added bundle_watcher to watch a folder for file changes, re #2.
Load the bundles on first run.
Fully working with non-authorized bundle.

* Store bundle's definitions in cache when starts.
* Bundle's definition is stored by filename.
* Each bundle's definition can contains multiple packages for different
services. Each is requested separately, but not asynchronously.
* The package's data are stored by "{bundle_id}^{package_name}".
* Added a higher supervisor to manage `bundle_watcher` and the
`cache_manager` (previously `spas_sup`).
Support multiple packages in one bundle.

* Returns a JSON object with package name as key, and its data
as value.
* Added some docs.
Clean up cached package when definition changes.

* Create an include file for some macros.
Implement OAuth for Twitter

* Added sample bundle for OAuth with Twitter.
* Uses `tim/erlang-oauth`.
* Adapted twitter example from `tim/erlang-oauth-examples`.
* Returns the authorize url when requesting bundle with OAuth.
* Handle callback from twitter and save access token.
* Not query data after authenticating yet.
OAUTH is now working fully

* Needed to put all OAUTH params as third argument `oauth_client:get`
and could not just use the full URL.
* `oauth` also returns string instead of binary. Needed to convert it.
Bump version